This invention relates to double walled manifold assemblies, particularly of the type which may be used to conduct a cryogenic fluid, such as liquid oxygen. In such manifolds two concentric conduits are provided, an inner conduit for conducting the cryogenic fluid and an outer conduit for conducting an inert gas in the space between conduits. Because of the temperature difference between the cryogenic fluid and the surrounding environment, both conduits of the manifold are advantageously provided with bellows sections to accommodate expansion and contraction of the inner and outer conduits at different rates. Such bellows sections are provided between each set of concentric tee portions of the manifold to maintain the tee portions in alignment with other structures as fluid and manifold temperatures vary.
Conventionally such manifolds are assembled using flange joints on the inner and outer conduits between alternating tee portions and bellows portions. The use of flanges for assembly of the manifold requires the provision of multiple seals at each joint and imposes extra weight and bulk at each joint.
It is therefore an object of the invention to provide a manifold assembly that is of lower weight and bulk and is capable of being fabricated by welding.